Tonotopic gradients in human primary auditory cortex: concurring evidence from high-resolution 7 T and 3 T fMRI

Brain Topogr. 2015 Jan;28(1):66-9. doi: 10.1007/s10548-014-0388-0. Epub 2014 Aug 7.

Abstract

The tonotopic representations within the primary auditory cortex (PAC) have been successfully mapped with ultra-high field fMRI. Here, we compared the reliability of this tonotopic mapping paradigm at 7 T with 1.5 mm spatial resolution with maps acquired at 3 T with the same stimulation paradigm, but with spatial resolutions of 1.8 and 2.4 mm. For all subjects, the mirror-symmetric gradients within PAC were highly similar at 7 T and 3 T and across renderings at different spatial resolutions; albeit with lower percent signal changes at 3 T. In contrast, the frequency maps outside PAC tended to suffer from a reduced BOLD contrast-to-noise ratio at 3 T for a 1.8 mm voxel size, while robust at 2.4 mm and at 1.5 mm at 7 T. Overall, our results showed the robustness of the phase-encoding paradigm used here to map tonotopic representations across scanners.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation
  • Auditory Cortex / physiology*
  • Auditory Perception / physiology*
  • Brain Mapping / instrumentation
  • Brain Mapping / methods
  • Cerebrovascular Circulation / physiology
  • Humans
  • Magnetic Resonance Imaging / instrumentation*
  • Magnetic Resonance Imaging / methods*
  • Oxygen / blood

Substances

  • Oxygen